Comparing the subject-event approach with existing BPM systems

Outlined in the text " Subject-event approach to the modeling of complex systems " method of analyzing and recording data, primarily intended for modeling business systems. The closest in name and, of course, content to the proposed subject-event-based approach should be recognized by two methods for describing business systems: the EPC charts (event-driven process chain, event-based process chain) and the subject-oriented approach (s-BPM) of the company Metasonic. Let's try to make a comparative analysis of these methods of enterprise modeling.

EPC charts

The subject-event approach is at odds with the EPC already at the level of the definition of an “event”. In the EPC, an event is considered to be a state that is fixed at the input or output of a certain function and defined by a set of certain parameters at some point in time. Although intuitively, such a definition of an event seems quite understandable, in general it contains a big moment of uncertainty: what is the state of what is at stake? the whole system? some object? the subject? On the other hand, many events that clearly affect the course of a business process do not fall under this definition: the EPC includes logical connectors, logical relationships, information flows and other elements that are not described as events, although, in fact, they are. This uncertainty is completely eliminated in the subject-event approach due to the unification of the description of all entities in the system - each of them is recorded as a set of events.

A significant advantage of the subject-event approach is the elimination of the multiplicity of types of links in modeling (control flow, message flow, logical links, associations, etc.) - all links are considered solely as causal (logical) links between events. Of course, one chain of related events can be designated as a process of changing a resource, another - as a management process, and a third - as a function of a subject, but in the original record all these processes are nothing but streams of standardly described events connected through execution conditions.

So, EPC diagrams from the position of a subject-event approach should be considered as a convenient and visual form of representing a fragment of an enterprise activity, reflecting the sequence of performance of a number of functions by one or several single-level subjects. Existing diagrams can serve as a data source for the formation of an event flow of an enterprise.
')

Subject-oriented approach (s-BPM)

From the point of view of the development of business process modeling tools, the subject-event approach should be considered as the next step after s-BPM. While preserving all the advantages of the latter, the subject-event approach has an important advantage in the form of unification of the description of subjects and objects. Due to this, the maximum approximation of the three aspects of the enterprise functioning is ensured: (1) direct activity, (2) its modeling and (3) operating with data. In the event stream in the same format, both the structure of the enterprise (the relationship between all its elements) and a complete description of all elements (both subjects and objects) are simultaneously recorded.

The basis of s-BPM is formed by acts (events) of relations between the subjects to which the functioning of the enterprise is reduced, or, more precisely, its activity is projected onto the level. Moving further in this direction, the subject-event approach as an informative element of the system proposes to consider any act of the subject , all of its relations with both subjects and objects, that is, any event that can affect the future state of the enterprise.

The principle of enterprise description in s-BPM and in the subject-event approach is close - many subjects are taken and their relations are fixed, - but in the event approach the subject is not considered as a system-forming factor. The subject is not predetermined to the description: like any object, it “emerges”, is revealed in the course of the formation of the event flow as a certain set of events. The main question in the event-based approach is not “what does this subject do?”, But “which subject performs this event and with what object?”. Attention moves from subject to event, making the latter a fundamental invariant: several human subjects can be combined into one subject or, conversely, one subject can be divided into several subjects, or even replaced with a software agent, and the object (resource) can also be changed to the other - and the event will remain the same. That is, the description of the enterprise itself through the flow of events is maximally adapted to modification and optimization, without changing the principles of organizing data and the formats of their description.

In response to the principle of “describing a process with only five characters”, put forward by s-BPM, the subject-event approach offers its own: “a description with just one symbol”. What principle follows from the understanding of the organism-enterprise as a stream of events: if we fix all the events, we get a complete description of the entire system . And no additional entities.

Although, of course, “one character” is just a slogan. The event flow of the enterprise itself can not be represented as a final model , as a logically separate scheme with fixed notation. The event flow should be understood as a multidimensional universum of events, which for analysis should be considered from some specific point of view, projected onto a certain plane. Let's say if we select events at the level of “subject-subject” relations, then we get a subject-oriented description (s-BPM). If we fix events at the beginning and at the end of a number of functions, we will have an EPC image of a system fragment. That is, from the position of the event-based approach, any of the existing schemes for describing business processes should be considered as a visualization method, as a projection of an organism-enterprise onto one of the possible semantic planes. And there may be an infinite set of such projections.

A significant advantage of the subject-event approach is that it does not offer a new scheme, the original model, but states that all existing schemes can, on the one hand, be reduced to the flow of events, and on the other, can be automatically extracted from it by fixing some parameters , for example, the level of the subject, the movement of a resource, etc.

findings

1. Let's briefly repeat the main principles of the subject-event approach:
2. description of the description at the lower level: only events exist, everything else - the subjects, objects (resources, documents) are described as sets of events;
3. combination of model and data - event flow contains full information about the system (description of objects and subjects, system structure);
4. the achievement of the relativity of the description - any object exists only for the specified subject, is described through a variety of events that it distinguishes;
5. description level formalization - subjects distinguishing the same objects are assigned to the same level, the description has integrity at each level;
6. coordination of descriptions at the highest level: all possible models (structural, functional, etc.) are reduced to a common stream of elementary events for them.

At its core, the subject-event approach is not a method of organization, management, modernization, optimization, but only a universal platform for describing complex systems with time-distributed complexity. The choice of a management strategy and optimization can be proposed after a formal analysis of the structure of the system's event flow. But even the fact of an event description without “hanging” on it any management and optimization strategies gives us, on the one hand, a tool for visualizing the operation of the system at any levels and from the point of view of any subject, and on the other hand, formalizing all regulations and tools for their quick modification. After all, the regulations are nothing but a list of events performed by a certain subject and conditionally related to other events.

That is, one of the important advantages of the subject-event approach to the analysis of complex systems is the initial separation of the ontological description from the management and optimization methods. The system appears before us on several levels:

1. lower level of events containing complete information about the system;
2. the level of objects and subjects (which are presented in the form of sets of events);
3. the level of the hierarchy of event systems - processes, actions, activities and their relationship with objects and subjects;
4. the level of management and optimization presented by the schemes, models, reflecting the structure of the enterprise from various points of view.

Each level is both ideologically and programmatically built over the bottom as a structure of the elements of the latter, but ontologically all structures at all levels consist of elements of the lower level (events), can be reduced to it. That is, ontologically (and programmatically) events are not distinguished by levels, they are all elements of the system’s event flow.

It should be especially noted that the subject-event approach in itself is only a tool for describing complex systems and does not directly predetermine any methods of optimization and planning of enterprises. (Although the very fact of modeling the system’s event flow can reveal problems in its organization and suggest solutions.) However, it is a very unified and globally related description that can be considered as the basis for introducing and automating any methods of real-time optimization and planning.